Impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest outcomes in Japan

This study investigates the impact of the COVID-19 pandemic on pediatric out-of-hospital cardiac arrest (OHCA) outcomes in Japan, aiming to address a critical research gap. Analyzing data from the All-Japan Utstein registry covering pediatric OHCA cases from 2018 to 2021, the study observed no significant changes in one-month survival, neurological outcomes, or overall performance when comparing the pre-pandemic (2018–2019) and pandemic (2020–2021) periods among 6765 cases. However, a notable reduction in pre-hospital return of spontaneous circulation (ROSC) during the pandemic (15.1–13.1%, p = .020) was identified. Bystander-initiated chest compressions and rescue breaths declined (71.1–65.8%, 22.3–13.0%, respectively; both p < .001), while bystander-initiated automated external defibrillator (AED) use increased (3.7–4.9%, p = .029). Multivariate logistic regression analyses identified factors associated with reduced pre-hospital ROSC during the pandemic. Post-pandemic, there was no noticeable change in the one-month survival rate. The lack of significant change in survival may be attributed to the negative effects of reduced chest compressions and ventilation being offset by the positive impact of widespread AED availability in Japan. These findings underscore the importance of innovative tools and systems for safe bystander cardiopulmonary resuscitation during a pandemic, providing insights to optimize pediatric OHCA care.


Results
Between 2018 and 2021, data from 6,765 pediatric OHCA patients were recorded and analyzed.When comparing pre-COVID- 19 (2018-2019) and during-COVID-19 (2020-2021) periods, there were no significant changes observed in the one-month survival proportion, CPC, or OPC.However, the proportion of prehospital ROSC significantly decreased after the onset of the COVID-19 pandemic (Table 1).The causes of cardiac arrest and the initial electrocardiographic waveform at the time of emergency medical service contact were examined.No significant differences were observed between pre-COVID-19 period group and during-COVID-19 period group.The details are presented in Table 1.
Furthermore, following the COVID-19 pandemic, the proportions of bystander-initiated chest compressions and rescue breaths by the bystander significantly decreased.On the other hand, the proportion of automated external defibrillator (AED) use by the general public significantly increased.To explore the factors contributing to the decreased proportion of prehospital ROSC during the pandemic, a multivariate logistic regression analysis was conducted.The results indicated that all of the following were significantly associated: "witnessed cardiac arrest", "bystander-initiated chest compressions", "bystander-initiated rescue breaths", "bystander AED use", "VF or pulseless VT", and "Time from call ambulance to hospital" (Table 2).The results of the multiple imputation were consistent with the previously mentioned findings.

Discussion
Our study, for the first time globally, has uncovered a significant reduction in the prehospital ROSC among pediatric OHCA patients following the COVID-19 pandemic, without any observed changes in the one-month survival rate.Additionally, our findings highlight the crucial associations between "witnessed cardiac arrest", "bystander-initiated chest compressions", "bystander-initiated rescue breaths", "bystander AED use", "VF or pulseless VT", and "Time from call ambulance to hospital" with the prehospital ROSC proportions in pediatric OHCA patients.
A noteworthy observation is the apparent decrease in the proportions of "bystander-initiated chest compression" and "bystander-initiated rescue breath" for pediatric OHCA patients after the onset of the COVID-19 pandemic.These declines are believed to be influenced by a general tendency among the public to avoid contact with others due to fear of COVID-19 infection 13,14 .Particularly, the decrease in rescue breaths may reflect the psychological concern of rescuers regarding the risk of exposure to others' bodily fluids during the COVID-19 www.nature.com/scientificreports/pandemic.If the pandemic duration in Japan were more prolonged, or if there were a higher number of COVID-19-related fatalities, the one-month survival rates might have declined further due to increased avoidance of interpersonal contact.Further analysis is warranted to explore these possibilities.
In our study, deterioration was observed only in the ROSC after the onset of the COVID-19 pandemic, with no changes noted in the one-month survival rate and neurological outcomes.Explaining all the reasons for this phenomenon is challenging, however, we focus on that the proportion of "bystander AED use" for pediatric  OHCA patients has increased after the COVID-19 pandemic.This can be attributed to the yearly increase in the number of AED installations in Japan and the advancements in CPR education 15,16 .As of 2019, Japan boasted a world-leading AED installation rate of 45.4 units per 10,000 people 17 .The authors believe that the rapid proliferation of AEDs in Japan may have contributed to some extent in preventing the deterioration of one-month survival rates and neurological outcomes.Moreover, taking into account the meta-analysis indicating an increase in OHCA at home due to COVID-19 18 , it becomes apparent that if the management of OHCA at home improves, there is potential for further improvement in OHCA survival rates.Hence, effective consideration of not only the increase in the number of AEDs but also their placement locations is essential.In this study, the reason for the decrease in Dispatcher CPR instruction during the COVID-19 pandemic is unclear.Reports from Japan suggest both an increase in Dispatcher CPR instruction during the COVID-19 pandemic [19][20][21] and no significant change 22 .While the importance of Dispatcher CPR instruction has been increasingly recognized over the years, it is possible that the strain on the emergency medical system that occurred in Japan during the COVID-19 pandemic may have contributed to the decrease in Dispatcher CPR instruction 23 .Further investigation is needed on this point.
There is a previous study that examined the impact of the COVID-19 pandemic on pediatric OHCA in Japan 24 .This study reported that the COVID-19 outbreak did not affect the ROSC or survival rates of pediatric OHCA, which differs from our findings.The previous study evaluated two groups of pediatric OHCA cases from 2015 to 2019 and 2020.We are concerned about the impact of the increasing number of AED installations and the spread of CPR education on the study results, and thus, we evaluated two groups from just before the COVID-19 outbreak in 2018-2019 and during the outbreak in 2020-2021.This difference in evaluation periods between the previous study and ours may contribute to the discrepancy in results.
A limitation of this study is the lack of information on the COVID-19 infection status of the targeted patients in the All-Japan Utstein registry data.Besides, in this registry, the evaluation of the attribute of bystander and the location of out-of-hospital cardiac arrests is inadequate.Since differences in the location of occurrence may affect survival rates, further investigation is necessary.Nevertheless, our findings in this study underscore the importance of reinforcing bystander CPR efforts and AED usage even during the COVID-19 pandemic, emphasizing that these interventions play a crucial role in improving outcomes for pediatric OHCA patients.There is a call for the development of tools and systems that enable bystanders to perform CPR without hesitation while protecting themselves from viral infections.
In conclusion, despite the formidable challenges posed by the COVID-19 pandemic, our study emphasizes the paramount importance of reinforcing bystander CPR efforts and utilizing AEDs in improving outcomes for pediatric OHCA cases.Based on the findings of this study, to enhance outcomes for pediatric OHCA patients, further promotion and awareness of CPR and AED utilization are needed.Additionally, promoting safe bystander CPR during a pandemic requires the development and widespread distribution of pediatric pocket resuscitation masks designed to protect bystanders from infectious diseases, along with the broad implementation of rescue gloves, which are deemed essential.

Table 1 .
Characteristics of the pediatric OHCA patients (N = 6765).OHCA out-of-hospital cardiac arrest; ROSC return of spontaneous circulation; CPC Cerebral Performance Categories; OPC Overall Performance Categories; ECG electrocardiogram; VF ventricular fibrillization; VT ventricular tachycardia; PEA pulseless electrical activity; AED automated external defibrillator.Bold values denote statistical significance at p < .05.

Table 2 .
Multivariate logistic regression analysis for prehospital ROSC in all pediatric OHCA patients (N = 4970).OR odds ratio; CI confidence interval; AED automated external defibrillator.VF ventricular fibrillization; VT ventricular tachycardia.Bold values denote statistical significance at p < .05.